Scientific Opinion on the re-evaluation of sulfur dioxide (E 220), sodium sulfite (E 221), sodium bisulfite (E 222), sodium metabisulfite (E 223), potassium metabisulfite (E 224), calcium sulfite (E 226), calcium bisulfite (E 227) and potassium bisulfite (E 228) as food additives

The EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS) was asked to deliver a scientific opinion re-evaluating sulfur dioxide (E 220), sodium sulfite (E 221), sodium bisulfite (E 222), sodium metabisulfite (E 223), potassium metabisulfite (E 224), calcium sulfite (E 226), calcium bisulfite (E 227) and potassium bisulfite (E 228) when used as food additives. The Panel noted that sulfur dioxide, bisulfite and sulfite ions existed in a series of equilibria and that these would favour bisulfite ions at the pH of the stomach and sulfite ions at physiological pHs. Therefore, it was considered that once ingested, based on their capacity to form sulfite ions, read across between the different sulfite sources is possible; however, the Panel noted the uncertainties about the reactivity of sulfites in different foods and the resulting reaction products. The overall limited database did not indicate any concern for genotoxicity and did not report any effect in the available chronic, carcinogenicity and reprotoxicity studies after oral exposure in the diet, by gavage, or in the drinking water. A no observed adverse effect level (NOAEL) of 70 mg SO₂ equivalent/kg body weight (bw) per day was identified from a long-term toxicity study in rats. However, the Panel noted several uncertainties and limitations in the database and concluded that the current group acceptable daily intake (ADI) of 0.7 mg SO₂ equivalent/kg bw per day (derived using a default uncertainty factor) would remain adequate but should be considered temporary while the database was improved. The Panel recommended that the database and the temporary group ADI should be re-evaluated and noted that the recommended studies could require 5 years for completion. The Panel further concluded that exposure estimates to sulfur dioxide and sulfites were higher than the group ADI of 0.7 mg SO₂ equivalent/kg bw per day for all population groups.